Professor Grinspoon originally endeavored to write Marijuana Reconsidered in order to build a case against marijuana, but as his research progressed, he realized the complexities of the plant and was moved to advocate for legalization. He has testified before Congress, and as an expert witness in various legal proceedings, including the deportation hearings of John Lennon.

Lester Grinspoon is Associate Professor Emeritus of Psychiatry at Harvard Medical School and the author of several drug-related books, including Marijuana Reconsidered, Psychedelic Drugs Reconsidered, and Marijuana: The Forbidden Medicine. The first two were published during the 1970s, when it appeared cannabis was well on its way to nationwide decriminalization in the United States. The latter was published in 1993. It describes a variety of ailments for which cannabis ingestion may be indicated.